The Open Library aims to make a webpage for every book ever written. This website currently has links to more than 1.7 million books (and that keeps going up all the time). If you're looking for a specific book to read, use the search bar and type in the title or author's name. When you get your results, make sure the "Ebooks" box is checked so that the results only show you free books to read. Books are available in every language. This link is for their student library resources. Books are categorized by age appropriateness (preschool is päiväkoti and kindergarten is eskari) and by reading level, which starts at the 3rd-grade level.

Like any library, you have to create an account (thus need an email address) to check out books, but there are no fees. While they do ask for donations, you are not required to give money to use the website. If a book is currently checked out, you can get on a waitlist to be notified when the book becomes available.